Speed Limit Increases/Decreases

[torino72]

This is just one of those silly little things about speed limits/zones that I keep wondering about. In Trainz a new speed zone is reflected immediately when the loco reaches the speed sign if it is a decrease in allowed speed. However, if it is an increase in allowed speed the speed increase occurs only when the last car of the train passes the speed sign. On real North American railroads is this how speed increases/decreases work? And, on trains with only FREDs on the rear, how does the engineer know when the last car passes the speed sign? Is it a best quess based on him/her knowing the train length and simply watching the odometer?

 

[sniper297]

Yes. As for knowing the train length, he also KNOWS THE ROUTE. Even experienced engineers coming into a new division ride with another engineer familiar with the division before going on his own, so none of the grades, curves, speed signs or signals come as a surprise. Knowing the route and knowing the length of train he has today, he can easily estimate by familiar landmarks when the back of the train has passed the last sign or signal or switch, using different landmarks depending on the current train length.

If you saw the movie "Unstoppable", the conductor was yakking on his cell phone while hooking up cars (anyone on any kind of phone has only half his mind on what he's supposed to be doing) and forgot to uncouple the last five cars. The engineer was watching in the mirror as he pulled out, counting the cars, and noticed he had 5 cars more than he was supposed to. Later when the dispatcher ordered him to take a siding, he refused because he knew that the current length of his train wouldn't fit on that siding. He didn't have to think about it, guess, calculate, or even look up the length of the siding in question, because he was intimately familiar with the route. That's how real engineers know.

 

[rgcx]

Train crews receive paperwork about the assigned train prior to departure. One of the first of many things to do is to verify its train length. The crew has an EOT counter function that will correctly determine train length. Therefore, the hogger can hit the counter button when passing a speed increase sign or leaving a passing siding/loop and will know when it is safe to speed up.

 

[Dermmy]

Think about this;

you climb into the cab of the first of 5 locos and behind them is 10 thousand feet of intermodal. You get the green light and notch up. You started deep in the yard and had to clatter through twelve junctions (including two double slips) before you hit the main and pass the 50 mph sign. But you still have nine thousand, five hundred feet of train to nurse through those slips. Now do you see why you are still restricted to 15 mph?